Rotary plastic blow molding

Abstract

A rotary plastic blow molding machine (20) including a base (22), a wheel (24) mounted for rotation on the base about a rotational axis A and a programmable logic controller (PLC) (100) mounted on the wheel for rotation therewith to control operation of a plurality of mold stations (40) on the wheel. The blow molding machine (20) as disclosed also has at least one sensor (62) mounted on the wheel (24) for rotation therewith to sense an operating parameter of each mold station and to generate an associated operation signal. The PLC (100) is coupled to the at least one sensor (62), processes the sensed operation signal and controls the machine (20) operation in response to the signal.

What is claimed is: 
     
       1. A plastic blow molding machine comprising: a base;   a wheel mounted for rotation on the base about a rotational axis and including a plurality of mold stations positioned on the wheel about the rotational axis, each mold station being movable between an open position to receive a hot plastic parison and a closed position where the parison is enclosed within mold station for blow molding; and   programmable logic means mounted on the wheel for rotation therewith and coupled with the mold stations to control the machine operation.   
     
     
       2. The plastic blow molding machine of claim 1 further comprising at least one sensor for sensing a wheel operating parameter as the wheel rotates during operation of the machine. 
     
     
       3. The plastic blow molding machine of claim 1 further comprising sensing means mounted on the wheel for rotation therewith and coupled with the programmable logic means, to sense at least one operating parameter of each mold station upon rotation of the wheel on the base and to generate an associated operation signal, the programmable logic means processing the sensed operation signal and controlling the machine operation in response to the signal. 
     
     
       4. The plastic blow molding machine of claim 1 or 2 further comprising a rotary coupling between the base and the wheel, and control means located on the base side of the rotary coupling and being operable to provide at least one electrical control signal through the rotary coupling to the programmable logic means on the wheel to control the machine operation. 
     
     
       5. The plastic blow molding machine of claim 4 wherein the control means includes a machine operator console. 
     
     
       6. The plastic blow molding machine of claim 4 wherein the control means includes a second programmable logic means. 
     
     
       7. The plastic blow molding machine of claim 4 wherein the control means includes a machine operator console and a second programmable logic means. 
     
     
       8. The plastic blow molding machine of claim 4 further comprising actuating means controlled by the programmable logic means and the control means for operating the blow molding machine. 
     
     
       9. The plastic blow molding machine of claim 2 wherein the operating parameter is the cavity air pressure of the mold station. 
     
     
       10. The plastic blow molding machine of claim 3 wherein the sensing means comprises at least one transducer. 
     
     
       11. The plastic blow molding machine of claim 3 wherein the sensing means comprises at least one proximity switch. 
     
     
       12. A plastic blow molding machine comprising: a base;   a wheel mounted for rotation on the base about a rotational axis and including a plurality of mold stations positioned on the wheel about the rotational axis, each mold station including a mold movable between an open position to receive a hot plastic parison and a closed position where the parison is enclosed within the mold for blow molding;   a rotary coupling between the base and the wheel;   programmable logic means mounted on the wheel for rotation therewith and coupled with the mold stations to control the machine operation; and   control means located on the base side of the rotary coupling and being operable to provide at least one electrical control signal through the rotary coupling to the programmable logic means on the wheel to control the machine operation.   
     
     
       13. A plastic blow molding machine comprising: a base;   a wheel mounted for rotation on the base about a rotational axis and including a plurality of mold stations positioned on the wheel about the rotational axis, each mold station including a mold movable between an open position to receive a hot plastic parison and a closed position where the parison is enclosed within the mold for blow molding;   a rotary coupling between the base and the wheel;   sensing means mounted on the wheel for rotation therewith to sense at least one operating parameter of each mold station upon rotation of the wheel on the base and to generate an associated operation signal;   programmable logic means mounted on the wheel for rotation therewith and coupled with the sensing means to process the sensed operation signal and control the machine operation in response to the signal;   control means located on the base side of the rotary coupling and being operable to provide at least one electrical control signal through the rotary coupling to the programmable logic means on the wheel to control the machine operation; and   actuating means controlled by the programmable logic means and the control means for operating the blow molding machine.   
     
     
       14. A method for controlling a plastic blow molding machine including a base and a wheel mounted for rotation on the base about a rotational axis, the wheel including a plurality of mold stations positioned about the rotational axis, the method comprising: rotating the wheel with a programmable logic means mounted thereon for rotation therewith;   generating at least one electrical operation signal based on an associated mold station operating parameter;   processing the electrical operation signal by the programmable logic means mounted on the wheel; and   controlling the machine operation by the programmable logic means in response to the processed electrical operation signal.   
     
     
       15. The method of claim 14 further wherein the wheel is rotated with a rotary coupling between the base and the wheel, and wherein a control means located on the base side of the rotary coupling is operated to provide an electrical control signal through the rotary coupling to the programmable logic means on the wheel to control the machine operation. 
     
     
       16. The method of claim 14 further wherein the mold station operating parameter is sensed by a sensing means mounted on the wheel for rotation with the wheel. 
     
     
       17. The method of claim 14 wherein the operating parameter sensed is the mold station cavity air pressure. 
     
     
       18. The method of claim 15 wherein the control means used includes a machine operator console. 
     
     
       19. The method of claim 15 wherein the control means used includes a second programmable logic means. 
     
     
       20. A method for controlling a plastic blow molding machine including a base and a wheel mounted for rotation on the base about a rotational axis, the wheel including a plurality of mold stations positioned about the rotational axis, the method comprising: rotating the wheel with a rotary coupling between the base and the wheel, and with a programmable logic means mounted on the wheel for rotation therewith;   generating at least one electrical operation signal based on an associated mold station operating parameter;   processing the electrical operation signal by the programmable logic means mounted on the wheel; and   controlling the machine operation by the programmable logic means in response to the processed electrical operation signal.   
     
     
       21. A method for controlling a plastic blow molding machine including a base and a wheel mounted for rotation on the base about a rotational axis, the wheel including a plurality of mold stations positioned about the rotational axis, the method comprising: rotating the wheel with a rotary coupling between the base and the wheel, and with a programmable logic means mounted on the wheel for rotation therewith;   generating at least one electrical operation signal based on an associated mold station operating parameter;   processing the electrical operation signal by the programmable logic means mounted on the wheel; and   controlling the machine operation by the programmable logic means mounted on the wheel and a control means located on the base side of the rotary coupling, which provides an electrical control signal through the rotary coupling to the programmable logic means on the wheel, to control the machine operation in response to the processed electrical operation signal.